Okay to start this out Hello everyone ...... Now to the problem My wife and I recently bought this house that was built in 1964. Well after fourty something years termites ate the paper backing in certan areas of the sheetrock ceiling, also one of the 2"x6" rafters has a slight bow to it making the ceiling any wich way but flat. This problem has become to be a eye sore . Question is can I leave the existing sheetrock and rip some firing strips to lay new rock? Reason being before I bought the house the previous owner had blown insulation over the existing fiberglass thus making the job a little cumbersom. Will Adding 1/2" sheets be to much weight for the 2x6"joists? Please HELP Me

You will be adding even more weight to ceiling joists that have already started to sag.

Maybe you could cut the existing ceiling into strips. Then you could take down a section at a time. You could push wire hangers in between the joists to hold the insulation up until you get all of the ceiling down and replaced.

The wire hangers are sold to be used as permanent support under floor
insulation.

Well my brother and I did some detective work today and come to find out the previous owner had a wall removed. Thats fine and all but the wall that was removed happend to be a load bearing wall. I will follow your directions and lift the joist then attach them to the rafter but after we constuct a header to help take the load off. I will keep you posted on the project.